Even though computer system is developed and improved so much, it still needs an input apparatus for users to input their commands or instructions to the computer system to operate it or for the computer system to execute the desired jobs. Typically, a conventional input apparatus needs not to record the working status and important data during its operations, and there is no data lost issue after its power is turned off, so that it needs no specific memory for these purposes, and it can still work normally when the computer system is turned off and restarted. Such art is referred to the microprocessor-based keyboard/display unit for configuring a control instrument proposed by U.S. Pat. No. 4,431,988 issued to Molusis et al. as an example. However, the functions provided by conventional input apparatus are almost for human-machine interfaces, by which users trigger the signal and immediately transmit the triggered signal to the computer mainframe to accomplish the desired operations. For more detail, readers are referred to the reconfigured keyboard proposed by U.S. Pat. No. 4,688,020 issued to Kuehneman et al. as an example. To accomplish the functions of human-machine interfaces, a conventional input apparatus is required to continuously scan its receiving unit or the like to detect the trigger signal, for example, a conventional keyboard always scans its keys, reads the key values, codes it properly, and sends out the key codes at an appropriate time.
Another conventional input apparatus has a built-in card reader to read smart cards. However, such art has the functions in an additional manner instead of combinational manner, and the data accessed to the smart card have no direct relations with the input apparatus itself. In other words, such input apparatus is used as a tool to access data only, and finally the accessed data is still transmitted to the computer mainframe. It is referred to the calculator keyboard with user-defined function keys and programmable modified interactive label for certain function keys of U.S. Pat. No. 4,823,311 issued to Hunter et al. for example for such art. There are still several other arts for computer keyboards having the functions of self-defined hot keys, while they all accomplish the key definitions by software programs. Therefore, once the power is turned off, the memory content of the keyboard is lost, no matter the definitions and the software programs are stored within the keyboard or the random access memory (RAM) of the computer mainframe.
In general, conventional input apparatus is very limited in its functions, and can be connected to specific interfaces only. Furthermore, the definitions of its keys and the coding methods thereof are constantly, and special software and hardware are needed for its applications, which makes it impossible to be multi-functional.